A passenger plane carrying 71 people from Bangladesh crashed and burst into flames as it landed Monday in Kathmandu, Nepal’s capital, killing at least 50 people, officials and witnesses said.

The exact number of dead and injured remained unclear amid the chaos of the crash and the rush of badly injured people to nearby hospitals, but Brig. Gen. Gokul Bhandari, the Nepal army spokesman, said it was clear that at least 50 people had died. Officials at Kathmandu Medical College, the closest hospital to the airport, said they were treating 16 survivors.

US-Bangla Airlines flight BS211 from Dhaka to Kathmandu was carrying 67 passengers and four crew members, according to an airline spokesman.

An AP journalist who arrived at the scene soon after the crash saw the US-Bangla Airlines twin-propeller plane broken into several large pieces, with dozens of firefighters and rescue workers clustered around the wreckage in a grassy field near the runway. Hundreds of people stood on a nearby hill, staring down at what remained of the Bombardier Dash 8.

The plane swerved repeatedly as it prepared to land in Kathmandu, said Amanda Summers, an American working in Nepal. The crowded city sits in a valley in the Himalayan foothills.

Nepalese rescuers stand near a passenger plane from Bangladesh that crashed at the airport in Kathmandu, Nepal.

AP Photo/Niranjan Shreshta

“It was flying so low I thought it was going to run into the mountains,” said Summers, who watched the crash from the terrace of her home office, not far from the airport. “All of a sudden there was a blast and then another blast.”

Fire crews put out the flames quickly, perhaps within a minute, she said, though for a time clouds of thick, dark smoke rose into the sky above the city.

The plane had circled the airport twice as it waited for clearance to land, Mohammed Selim, the airline’s manager in Kathmandu, told Dhaka-based Somoy TV station by telephone.

The airline, part of US-Bangla Group, is based in the Bangladeshi capital, Dhaka, and flies to several domestic and international destinations. The parent company is involved in a number of industries, including real estate, education and agriculture.

Kathmandu’s airport has been the site of several deadly crashes. In September 2012, a Sita Air turboprop plane carrying trekkers to Mount Everest hit a bird and crashed shortly after takeoff, killing all 19 on board.